Apparatus for separating solid materials by suspension



APPARATUS FOR SEPARATING SOLID MATERIALS BY SUSPENSION M. DRU

July 9, 1957 2 Sheets-Sheet 1 Filed June 18, 1956 INVENTOR. MAECEL 02 0 y A A July 9, 1957 M. DRU 2,798,606

APPARATUS FOR SEPARATING SOLID MATERIALS BY SUSPENSION led June 18, 1956 2 Sheets-Sheet 2 INVENTOR. M42654 D20 A 770zA/E Y 2,798,606 Patented July 9, 1957 APPARATUS FOR SEPARATING SOLID MATERIALS BY SUSPENSION Marcel Dru, Fontainebleau, France, assignor to Ste Jaruza A. G. Chur, Zurich, Switzerland, a Swiss company Application June 18, 1956, Serial No. 592,143 Claims priority, application France June 18, 1955 7 Claims. (Cl. 209173) This invention relates to apparatus for separating solid materials and has more particular reference to apparatus for separating solid materials of different specific gravities by means of a suspension.

One object of the present invention is to provide novel and improved apparatus for separating solid materials of different specific gravities by means of a suspension, as for example, in coal washing installations, for separating slate, sand, or other heavy constituents from the coal.

Another object of the present invention is to provide apparatus, as characterized above, including a sedimentation vat for receiving the dense liquid and solid materials to be treated; a lifting wheel for raising the sink products from the vat; a draining surface positioned adjacent the vat for receiving the overflow of dense liquid and float products; a receptacle positioned below said draining device for receiving the dense liquid drained therethrough; and means including a rotatable tank for receiving the drained liquid from said receptacle and recycling it back into the vat.

A further object of the present invention is to provide apparatus, as characterized above, wherein the lifting wheel and rotatable tank are mounted on a common inclined shaft for rotation therewith with said tank positioned below said lifting wheel.

Other objects and advantages of the invention will appear in the following specification when considered with the accompanying drawings, wherein:

Fig. l is a plan view of one embodiment of apparatus construction in accordance with the present invention;

Fig. 2 is a side elevational view of the apparatus shown in Fig. 1, taken on line 2-2 of Fig. 3;

1 Fig. 3 is a vertical sectional view taken on line 3-3 of Fig. 1; and

Fig. 4 is a fragmentary vertical sectional view showing a modified form of apparatus for float extraction.

The present invention is an improvement over that shown and claimed in my prior Patent No. 2,678,727, granted May 18, 1954, for Separating Solid Materials by Suspension.

My aforesaid prior patent discloses apparatus for separating solid materials of different specific gravities into two classes and comprises a large vat into which dense liquid and the material to be separated are delivered and wherein a liquid level is maintained so that the float or lighter products are evacuated by overflowing with the liquid while the sink or heavier products fall to the bottorn, from where they are removed by means of a rotating paddle wheel mounted in an inclined annular casing arranged at and opening into one side of the vat. The raised products being evacuated through an opening in the top portion of the annular casing.

The present invention provides improved means for raising the sink or heavy products and provides for these products to be discharged at the same end of the vat where the float or light products are discharged.

The present invention further provides means for recycling the dense liquid discharged with the float products back into the washing bed of the vat.

Referring now to the drawings, there is illustrated, in Figs. 1, 2 and 3, one embodiment of apparatus constructed in accordance with the present invention. As there shown, the apparatus comprises an elongated, generally rectangular sedimentation vat or wash box 10, having an overflow sill or Weir 11 on its outlet end and into the opposite end of which are delivered the dense liquid and the solid materials to be separated; an inclined open-top casing, indicated generally at 12, positioned at one: side of the vat and with its lower end opening into and forming the bottom portion of the vat; an inclined shaft 13 extending up through the bottom Wall of the casing in a direction normal to the plane of inclination of the casing to the vat; a lifting wheel, indicated generally at 14, mounted on said shaft within said casing for lifting the sink products as they fall to the bottom of the vat; an inclined chute 15 having its upper end positioned to receive the sink prod ucts as they are discharged from the lifting wheel and its lower end positioned to discharge the sink products pass ing therethrough at the end of the vat over which the float products are discharged; an inclined open-top rotatable cylindrical tank 16 having a plurality of buckets formed therein mounted on said shaft for rotation therewith; a draining screen 17 positioned to receive the float products as they pass over the weir; a receiving tank 18 positioned below the draining screen 17 to recevie the dense liquid drained from the float products as they cross the draining screen and discharge it into the lower end portion of the rotatable tank 16, where it will be lifted by the buckets therein as the tank rotates; and a fixed tank 19 positioned between the rotatable inclined cylindrical tank 16 and the fixed inclined casing 12 for receiving the dense liquid discharged from the buckets of the rotatable tank 16. t

The sedimentation tank or vat 10 is generally similar in construction to the sedimentation vat shown in my aforesaid patent. It is shown as an elongated, generally rectangular vat having vertical side walls 20, 21 and an inclined bottom wall 22 which merges into the bottom end portion of the inclined casing 12.

The inclined casing 12, which houses the lifting wheel 14 and helps form the bottom portion of the vat, is shown as having an inclined disc shaped bottom wall 23 having its upper end truncated as indicated at 24 and through which the shaft 13 extends, and a side wall 25 extending upwardly from the rounded edge portion of the bottom wall. The lowermost portion of the bottom wall 23 of the inclined casing 12 is provided with an opening 26 for a purpose hereinafter to be described. The lower portion of the bottom .wall of the inclined casing 12, in effect, forms a side wall of the vat. The side wall 20 of the vat adjacent the casing acts as a battle member preventing the flow of the float or lighter products from the vat into the casing.

The lifting wheel 14 is shown as comprising an annular plate 27 having an upstanding flange formed around its outer periphery forming an outer wall 28; a convex annular disc 29 fixedly mounted on a hub fixedl on the shaft 13 and having its outer peripheral edge secured to the inner peripheral edge of the annular plate 27; and a plu rality of baskets, indicated generally at 30. The baskets may be of any suitable construction and as shown, each comprises a bottom wall formed by the annular plate 27, an outer end wall formed by the flange 28 a top wall member 31, and a perforated side wall member 32 positioned to be inclined with respect to the radius of the wheel. The buckets all open in an inwardly radial direction with respect to the wheel.

The shaft 13 is journaled in suitable fixed upper and lower bearings 33, 34, respectively, and is driven by any suitable means, such as a worm wheel 35 fixed on the bottom wall of the inclined tank 16 and driven by a worm 36 on a shaft 37 adapted to be driven by any suitable means (not shown).

The inclination of the casing 12 and the height of the upper bearing of the shaft are such that the upper bearing is above the level of the dense liquid in the vat The chute for receiving the sink or heavy products lifted by the lifting Wheel 14, may be of any suitable construction. It is shown as a trough-like structure having a closed bottom 38 and upstanding side walls 39, 40. The chute has its upper receiving end positioned to receive the heavy products as they fall from the baskets or buckets in the lifting wheel, and its lower end positioned to discharge the heavy products gravity-flowing therethrough into an open-top chute 41 which discharges them from the apparatus.

The rotatable cylindrical tank 16 is fixedly mounted on the shaft 13 for rotation therewith and is shown as comprising a disc-shaped bottom wall 42 connected to a hub member fixed on the shaft 13 and extending through the bottom wall, and a side wall 43 extending upwardly from the outer periphery of the bottom wall. The bottom wall of the rotatable tank 16 isaxially spaced below the bottom wall of the fixed inclined casing 12 and the side wall of the rotatable tank 16 is radially spaced outwardly of the side wall of the casing 12 so that the rotatable tank 16 encircles and partially encloses the fixed casing 12.

The rotatable tank 16 has a plurality of circumferentially spaced buckets formed therein in any suitable manner. As shown, the buckets are formed by an annular plate 44 spaced above the bottom wall 42 with its outer peripheral edge fixedly secured to the side Wall 43 of the tank and with the space between the plates 42.- and 44 divided into a plurality of inwardly and radially opening compartments or buckets by means of a plurality of circumferentially spaced radially extending partition members 45. Each of the buckets has an opening 46 formed in the outer end portion of its. top wall for a purpose hereinafter to be described.

The draining screen 17 may be of any usual construction and is shown as comprising anelongated perforated or reticulated bottom Wall member 47 having vertical side walls 48, 49. The draining screen is mounted adjacent the discharge end of the vat below the overflow sill or weir 11, in position to receive the overflow liquid and float products on its screening surface.

The tank 18 for receiving the overflow dense liquid and the dense liquid drained from the float products as they pass over the draining screen 17, may be of any suitable construction. It is shown as having an open top positioned below the screen 17' and the overflow weir 11 and having downwardly and inwardly inclined side walls 56, 51, 52., 53 terminating in a rectangular in cross section conduit 54 forming a passageway opening into the rotatable tank 16 so that the dense liquid received in the tank 18 will pass into the rotatable tank 16 and be received on top of the annular plate 44 and pass through the opening 46 into the buckets 42 to be lifted thereby as the tank rotates.

The fixed tank 19 which receives the dense liquid lifted by the buckets in the rotatable tank 16 as it rotates may be of any suitable construction. It is shown as being formed by a generally disc-shaped plate 55 positioned between the inclined casing 12 and the rotatable tank 16, with the shaft 13 extending therethrough, which forms the bottom wall of the tank. The bottom plate 23 of the casing 12 forms the top wall of the tank 19 and the side wall is formed by an arc-shaped plate 56 which forms an extension of the side wall of the casing 12. The upper end portion of the bottom wall 55 of the tank 19 is truncated and bent outwardly and upwardly, as shown at 57 (see Fig. 3), to bring the upper edge portion of the plate 56 substantially in alignment with the openings, in the buckets of the rotatable tank 16 so that as. the dense liquid is discharged from the buckets it will fall into the fixed tank 19. The dense liquid received in the tank 19 passes upwardly through the opening 26 formed in the lower portion of the bottom wall 23 of the inclined casing 12 and rejoins the dense liquid in the washing box of the vat. The sedimentation vat and the upper and lower shaft bearings are supported by a suitable framework, indicated generally at 58.

The operation of the apparatus is believed apparent. The raw material to be treated is fed into the washing box It the sink products or heavy fractions fall into the bottom of the wash box into the series of baskets of the lifting wheel and are lifted by the wheel, as it rotates, and, at an elevated point in the path of rotation slide out of the baskets of the wheel into the chute mounted to receive them, and are discharged by the chute at the end of the vat near the light fraction discharge point. The float products or light fractions are discharged over the overflow sill or weir with the overflow of dense liquid and fall onto the draining screen, where they are drained of dense liquid.

The dense liquid drained from the float products and the overflow dense liquid pass through the draining screen into the receptacle 18 and from there into the lower portion of the rotatable tank 16, where they pass into the buckets therein and are lifted by the buckets as the tank rotates and, at an elevated point in the path of rotation, flow out of the buckets into the fixed tank 19 and from tank 19; pass through opening 26 back into the washing box. Thus, almost all of the dense liquid discharged from the washing box with the float products is recovered and returned to the washing box, and only a very slight amount of make-up is suflicient to replace the small amount carried away by the products after being drained.

In order to reduce to a minimum the dimensions of the rotatable tank 16, the fixed weir 11 may be replaced by a vibrating weir 59, as illustrated in Fig. 4. In this case, the liquid level in the washing bath is only very slightly above the top edge of the Washing box, as it is the vibration of the vibrating weir which enables the float products to pass from the washing bed onto a spraying screen (not shown). The vibrating weir 59 may be of any suitable usual construction and is vibrated by any suitable usual means (not shown). It is positioned over a drainage receiving tank or receptacle 6%) which receives the dense liquid passing through the perforated bottom wall of the vibrating weir and the dense liquid overflow, and discharges the same back into the rotatable tank 16 of the apparatus.

From the foregoing, it readily will be seen that there has been provided novel and improved. apparatus for'the densimetric separation of solid materials by a dense liquid in a separation vessel in the form of an elongated vat provided with a rotary wheel for extracting the heavy fractions, and wherein means are provided for recycling the dense liquid discharged from the washing bed in the separation vessel.

Obviously, the invention is not restricted to. the particular embodiments thereof herein shown and described.

What is claimed is:

1. In apparatus for the densimetric separation of solid material by a dense liquid to produce fractions of dififerent specific gravities of the class wherein a sedimentation vat adapted to receive the dense liquid and the solid material to be treated is provided with a draining surface adjacent thereto for receiving the discharge of the dense liquid and the float products and with lifting means for lifting the sink products for evacuation from said vat, the combination with said vat and said draining surface of means for recycling the dense liquid passing through said draining surface back into said vat, including a receptacle positioned to receive the dense liquid as it flows through said draining surface, a rotatable tank rotatable about an inclined axis and provided with a circular row of buckets, a onduit connected to the bottom end of said receptacle and having its delivery end positioned to discharge dense liquid gravity-flowing th'erethrough into said rotatable tank; and an inclined passageway having its upper receiving end positioned below the upper part of the path of travel of the buckets in said rotatable tank and its lower end positioned to discharge into said vat, whereby as said rotatable tank rotates the drainage dense liquid will be lifted and deposited in said passageway for gravity flow back into said vat.

2. Apparatus as set forth in claim 1, wherein said drain-- ing surface is in the form of a vibrating weir.

3. Apparatus as set forth in claim 1, wherein said rotatable tank is in the form of an open-top cylindrical vessel.

4. Apparatus as set forth in claim 2, wherein said lifting means is in the form of a lifting wheel carrying a plurality of baskets and mounted for rotation about an inclined axis, and wherein the aXis of said rotatable tank is concentric with the axis of said lifting wheel.

5. Apparatus as set forth in claim 4, wherein said lifting wheel is fixed on an inclined shaft for rotation therewith and wherein said rotatable tank is fixed on said inclined shaft for rotation therewith and is positioned below said lifting Wheel.

6. In an apparatus for separating solid materials having different specific gravities, comprising an elongated sedimentation vat for holding a body of dense liquid, said vat having an overflow sill along one end over which the float products are discharged with overflow dense liquid onto a draining screen positioned below the overflow sill; an inclined open-top casing positioned at one side of said vat with its lower end opening into and forming the bottom portion of the vat to receive the sink products, the side wall of the vat adjacent the casing acting as a baffle member preventing the flow of the float products from the vat into the casing; a shaft extending upwardly through the bottom of said casing in a direction normal to the plane of inclination of said casing to said vat; a lifting wheel mounted in said casing and fixedly connected to said shaft for rotation therewith, said lifting wheel carrying a plurality of circumferentially spaced blades positioned adjacent its outer periphery with the spaces between the blades forming baskets in which the sink products are received when they sink into the bottom of the vat and are lifted by the baskets as the wheel rotates; a fixed inclined chute having its upper receiving end positioned to receive the sink'products as they are discharged from said baskets at an elevated point in their path of rotation, and its lower discharge end positioned to discharge the sink products gravity-flowing therethrough adjacent one end of the vat; an open-top cylindrical tank fixedly mounted on said shaft for rotation therewith, said cylindrical tank being positioned below said inclined casing and having a plurality of circumferentially spaced inwardly opening buckets formed therein; a fixed receptacle positioned below said overflow sill and said draining screen to receive overflow dense liquid drained from said float products; a conduit having its upper receiving end connected to said receptacle and its lower end positioned to discharge the dense liquid gravity-flowing therethrough into the lower portion of said cylindrical tank; an inclined passageway formed between said inclined casing and said cylindrical tank and having its upper receiving end positioned below the upper part of the path of travel of the buckets in said cylindrical tank and its lower end communicating with the lower end portion of said inclined casing whereby as said cylindrical tank rotates the drained dense liquid received therein will be lifted and discharged into said passageway for gravity-flow back into said sedimentation vat.

7. Apparatus as set forth in claim 6, wherein said overflow sill and said draining surface are in the form of a vibrating weir having a perforated bottom wall positioned over said receptacle so that the overflow dense liquid will drain through the bottom of said weir as the float products pass across the weir. 

